William de Hainaut

William I, Count of Hainaut (1286-7 June 1337) was the Count of Zeeland from 1304 until his death.

Biography
Willem van Hainaut was grandson of Henry V of Luxembourg, and he became heir to his father Jean II of Hainaut after the Battle of Courtrai in 1302. He fought Flanders until 1323, forcing them to renounce their claims to the County of Zeeland. William forged diplomatic alliances with Edward III of England and Ludwig IV of Germany by marrying his daughters to them, and in 1337 he backed Edward III in declaring war on France during the Hundred Years War. This alliance, caused by a Knights Templar plan to retake France, was threatening to the Assassins Order, who sanctioned his death.

Death
Assassin Louis de Grandpre headed to Antwerp, where William was planning to meet with an English diplomat. Grandpre entered the terrace of the estate, crowded by people, slaves, and guards, and found William meeting with the diplomat. He followed them into a smaller chamber, where the two talked in secret about a Templar plan. Grandpre interrupted them, killing both of them after running up to them and skewering them both with hidden blades. Hainaut, still wounded, asked Grandpre why he was murdered. He responded by saying that he should have been wiser in his choice of allies, but William told him that Edward was his son-in-law and he would stand by his family. He died shortly after, and Grandpre respected his loyalty.